Hi there, I've been following a tutorial and in it a Categories table has to be created, the tutorial gives the following sql

CREATE TABLE IF NOT EXISTS 'categories' (
'id' int (10) unsigned NOT NULL auto_increment,
'parent_id' int(11) NOT NULL default '0',
'name' varchar(50) character NOT NULL,
'description' varchar(200) character NOT NULL,
PRIMARY KEY ('id'),
KEY 'cat_parent_id' ('parent_id'),
KEY 'cat_name' ('name')
);

The last two lines (eg KEY 'cat_name' ('name')) I'm not too sure about what that means. I've googled and only found out that it might have something to do with indexes. From what I've read I understand indexes (sort of) but I can't find anywhere which uses that KEY instruction when creating a table. Any other article I find about indexes uses something like: CREATE INDEX IDX_CUSTOMER_LAST_NAME
on CUSTOMER (Last_Name)

Can anyone explain what exactly KEY does, and what the 'cat_name' ('name') beside it means, is cat_name and alias? Obviuosly 'name' is the column in the table that the instruction is dealing with.

confused...

in the CREATE (or ALTER) TABLE syntax, KEY is a synonym for INDEX

it's all explained quite nicely in the manual